Unable to tune sensorless homing on laser cutter

Drizz1le

Hello everyone,

Ive been trying to solve this issue for a few days now (after taking a month break lol) and now I'm really lost. I am unable to tune sensorless homing for my laser cutter. Below are the gcode files, and motor specifications.

The X length is 750-800 units
Stepper motor part number: 17HS16-2004S1

If anyone could send me corrected files or any help that would be great!

LMK if you need any other info.

Please note that the values in the current gcode files are probably not correct lol

homex.g

M400 ; Wait for current moves to finish
M913 X70 Y70 ; drop motor current to 70%
M400
G91 ; relative positioning
G1 H1 X-320.5 F1200 ; move quickly to X axis endstop and stop there (sensorless homing)
G90 ; absolute positioning
M400
M913 X100 Y100 ; return current to 100%
M400

config.g

; Configuration file for RepRapFirmware on Duet 3 Mini 5+ WiFi
; executed by the firmware on start-up
;
; generated by RepRapFirmware Configuration Tool v3.5.4 on Sun Aug 18 2024 18:47:56 GMT-0400 (Eastern Daylight Time)

; General
G90 ; absolute coordinates
M83 ; relative extruder moves
M550 P"Laser Duet 3" ; set hostname
M911 S19.8 R22 P"M913 X0 Y0 G91 M83 G1 Z3 E-5 F1000" ; set voltage thresholds and actions to run on power loss

; Accessories
M575 P1 S0 B57600 ; configure PanelDue support

; Network
M552 S1 ; configure WiFi adapter
M586 P0 S1 ; configure HTTP

; Smart Drivers
M569 P0.0 S0 D2 ; driver 0.0 goes forwards (X axis)
M569 P0.1 S1 D2 ; driver 0.1 goes forwards (Y axis)

; Motor Idle Current Reduction
M906 I30 ; set motor current idle factor
M84 S30 ; set motor current idle timeout

; Axes
M584 X0.0 Y0.1 ; set axis mapping
M350 X16 Y16 I1 ; configure microstepping with interpolation
M906 X1400 Y1400 ; Set motor currents to 1.4A for X and Y axes
M92 X80 Y80 ; configure steps per mm
M208 X0:750 Y0:200 ; set minimum and maximum axis limits
M566 X900 Y900 ; set maximum instantaneous speed changes (mm/min)
M203 X6000 Y6000 ; set maximum speeds (mm/min)
M201 X500 Y500 ; set accelerations (mm/s^2)

; Kinematics
M669 K1 ; configure CoreXY kinematics

; Endstops
M574 X1 S3 ; configure X axis endstop (sensorless)
M574 Y1 S3 ; configure Y axis endstop

; Lasers
M452 C"laser" F500 R255 S0 ; configure Laser port 

; Miscellaneous
M915 X Y S3 R1 F1 H200 ; Adjust H value as needed

dc42

@Drizz1le the TMC2209 drivers on the Duet 3 Mini need to be in stealthChop mode for stall detection to work, but you have them set to spreadCycle mode in your M569 command. Also your homing speed (1200mm/min) may be too slow for stall detection to work reliably. See https://docs.duet3d.com/en/User_manual/Connecting_hardware/Sensors_stall_detection#limitations-of-stall-detection and the following sections for more details.

Bear in mind that stall detection is not an accurate method of homing, so if you need precision then I recommend that you use endstop switches.